Biogeochemical Reduction Processes in a Hyper-Alkaline Leachate Affected Soil Profile
Biogeochemical Reduction Processes in a Hyper-Alkaline Leachate Affected Soil Profile
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DOI：
10.1080/01490451.2011.619638
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发表时间：
2012-01-01
影响因子：
2.3
通讯作者：
Stewart, Douglas I.
中科院分区：
文献类型：
--
作者：
Burke, Ian T.;Mortimer, Robert J. G.;Stewart, Douglas I.
高碱性的表面环境可以自然发生，也可以被富含氢氧化物的废物污染。这些地区产生的高pH值有可能导致高度专业化的微生物群落和不寻常的生物地球化学过程。本文报道了在pH值为12.3的地下饱和富有机质土层中发生的地球化学过程。土壤被困在方解石沉淀（凝灰岩）下面，这些方解石沉淀正在积聚，石灰窑废料的高碱性渗滤液正在向大气中排放。一群厌氧嗜碱细菌，由一种单一的、未识别的β -变形菌科共胞菌科细菌主导，已经在接近土壤表层的地方建立起来。这种细菌群似乎能够利用来自土壤有机质的电子供体还原硝酸盐。在硝酸盐还原区以下，0.5N HCl可提取铁（微生物有效铁的代表）中有很大一部分处于Fe（II）氧化态，这表明缺氧程度随着深度的增加而增加，表明微生物铁正在发生还原。本文有补充材料。请访问出版商的在线版《地球微生物学杂志》，查看免费的补充文件。
Hyperalkaline surface environments can occur naturally or because of contamination by hydroxide-rich wastes. The high pH produced in these areas has the potential to lead to highly specialized microbial communities and unusual biogeochemical processes. This article reports an investigation into the geochemical processes that are occurring in a buried, saturated, organic-rich soil layer at pH 12.3. The soil has been trapped beneath calcite precipitate (tufa) that is accumulating where highly alkaline leachate from a lime kiln waste tip is emerging to atmosphere. A population of anaerobic alkaliphilic bacteria dominated by a single, unidentified species within the Comamonadaceae family of beta-proteobacteria has established itself near the top of the soil layer. This bacterial population appears to be capable of nitrate reduction using electron donors derived from the soil organic matter. Below the zone of nitrate reduction a significant proportion of the 0.5N HCl extractable iron (a proxy for microbial available iron) is in the Fe(II) oxidation state, indicating there is increasing anoxia with depth and suggesting that microbial iron reduction is occurring. Supplemental materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the free supplemental files.